CHICAGO, April 20 /PRNewswire-FirstCall/ -- Archipelago Holdings, Inc. (PCX: AX), owner and operator of the Archipelago Exchange(SM) (ArcaEx(R)), the nation's first totally open, all-electronic stock exchange, announced that the company would hold its first quarter 2005 financial results call at 12:00 p.m. EDT tomorrow, Thursday, April 21, 2005.

    WHERE:  Via conference call and Internet; dial-in information is as

            follows:



    Dial-in number:  800.884.5695 (DOMESTIC)

                     617.786.2960 (INTERNATIONAL)



    Passcode:        55914470



    Web address:

     http://investor.archipelago.com/phoenix.zhtml?c=140290&p=irol-irhome

A replay of the call will be available beginning at 3:00pm EDT Thursday, April 21 and running through April 28. The replay can be accessed by dialing either 888-286-8010 or 617-801-6888. The pass-code is 67527145.

About Archipelago

Archipelago Holdings, Inc. (PCX: AX) owns and operates the Archipelago Exchange (ArcaEx). ArcaEx is the first totally open all-electronic stock market in the United States. Through its alliance with the Pacific Exchange, Inc., Archipelago operates ArcaEx as the exclusive equities trading facility of PCX Equities, Inc. Through ArcaEx, Archipelago customers can trade over 8,000 equity securities, including securities listed on the New York Stock Exchange(R), Nasdaq(R), American Stock Exchange(R) and Pacific Exchange(R). ArcaEx is regulated by the Pacific Exchange. The Archipelago ECN, a precursor to ArcaEx, was one of the four original ECNs, formed in December 1996 with Townsend Analytics.

Certain statements in this press release may contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on Archipelago's current expectations and involve risks and uncertainties that could cause Archipelago's actual results to differ materially from those set forth in the statements. There can be no assurance that such expectations will prove to be correct. Factors that could cause Archipelago's results to differ materially from current expectations include: general economic and business conditions, industry trends, competitive conditions, regulatory developments as well as other risks or factors identified in the Company's filings with the Securities Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2004 which is available on the Company's website at http://www.archipelago.com. You should not place undue reliance on forward- looking statements, which speak only as of the date of this press release. Except for any obligation to disclose material information under the Federal securities laws, Archipelago undertakes no obligation to release publicly any revisions to any forward-looking statements to reflect events or circumstances after the date of this press release.

     Contacts:

     Archipelago Holdings, Inc.

     Margaret Nagle, 312-442-7083 (Press)

     Patrick Murphy, 312-442-7005 (Investor Relations)

SOURCE  Archipelago Holdings, Inc.

    -0-                             04/20/2005

    /CONTACT:  Margaret Nagle, +1-312-442-7083, Press, or Patrick Murphy,

+1-312-442-7005, Investor Relations, both of Archipelago Holdings, Inc./

    /Web site:  http://www.archipelago.com /

    (AX)



CO:  Archipelago Holdings, Inc.

ST:  Illinois

IN:  FIN CPR

SU:  CCA



AA

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8097 04/20/2005 18:09 EDT http://www.prnewswire.com